I liked this episode actually. Echo was immediately interesting for me. I liked the backstory, but I couldn't help but think Kate needed some of that too. They just want you to trust that she is that good at martial arts and archery. Compare it to the little they did with the Echo backstory scene. They actually showed you she learned how to read people, and how to fight.
It's a little thing but, just seems weird in the same show 2 different approaches to show us training and skill levels.